My daily readings 06/04/2011

Opinionaided’s free iOS app allows users to get advice and opinions on the fly. Within the app, users can input a question, determine a category (i.e. relationships, politics) and submit it for other Opinionaided users to answer. You can also publish your questions to Facebook and Twitter. After a question is posted, fellow Opinionaided users can comment on the question and the app will calculate the percentage of users that responded positively or negatively. From there, consumers can reply back to the comments or create a new question for peers to vote on.

So what’s driving this much growth in users and engagement? Opinionaided founder Dan Kurani says that the ability to get real-time feedback at the point of decision-making is helping drive usage growth. On average it takes less than 2 minutes to get your first 10 responses to any question, says the company. And the simplicity of the app makes it appealing as well.

Interestingly, the average age of the Opinionaded user is 24, so perhaps usage also skews to a younger audience that is more engaged on devices like the iPhone. And while Opinionaided offers a web platform, Kurani says the company is seeing 90 percent of engagement on mobile.

while i like project euler, i find rosettacode to be more down-to-earth. in everyday life you’re much more likely to have to solve rosettacode’s tasks (eg download a page from the web, parse something, generate a bitmap, send a mail) than project euler’s math-based tasks.

Now you have two rectangles, each cut diagonally in half by a leg of the triangle. So there is exactly as much space inside the triangle as outside, which means the triangle must take up exactly half the box!

This is what a piece of mathematics looks and feels like. That little narrative is an example of the mathematician’s art: asking simple and elegant questions about our imaginary creations, and crafting satisfying and beautiful explanations. There is really nothing else quite like this realm of pure idea; it’s fascinating, it’s fun, and it’s free!

This is why it is so heartbreaking to see what is being done to mathematics in school. This rich and fascinating adventure of the imagination has been reduced to a sterile set of “facts” to be memorized and procedures to be followed. In place of a simple and natural question about shapes, and a creative and rewarding process of invention and discovery, students are treated to this:

“The area of a triangle is equal to one-half its base times its height.” Students are asked to memorize this formula and then “apply” it over and over in the “exercises.” Gone is the thrill, the joy, even the pain and frustration of the creative act. There is not even a problem anymore. The question has been asked and answered at the same time — there is nothing left for the student to do.

The problem itself is a lot like Lockhart’s triangle question — simple enough to entice the freshest beginner, sufficiently complicated to require some thought.

All it takes is a little hunger. You just have to want the answer.

That’s the pedagological ballgame: get your student to want to find something out. All that’s left after that is to make yourself available for hints and questions. “That student is taught the best who is told the least.”

Project Euler, named for the Swiss mathematician Leonhard Euler, is popular (more than 150,000 users have submitted 2,630,835 solutions) precisely because Colin Hughes — and later, a team of eight or nine hand-picked helpers — crafted problems that lots of people get the itch to solve. And it’s an effective teacher because those problems are arranged like the programs in the ORIC-1’s manual, in what Hughes calls an “inductive chain”:

This is an idea that’s long been familiar to video game designers, who know that players have the most fun when they’re pushed always to the edge of their ability. The trick is to craft a ladder of increasingly difficult levels, each one building on the last. New skills are introduced with an easier version of a challenge — a quick demonstration that’s hard to screw up — and certified with a harder version, the idea being to only let players move on when they’ve shown that they’re ready. The result is a gradual ratcheting up the learning curve.

On top of this there is one brilliant feature: once you get the right answer you’re given access to a forum where successful solvers share their approaches. It’s the ideal time to pick up new ideas — after you’ve wrapped your head around a problem enough to solve it.

This is also why a lot of experienced programmers use Project Euler to learn a new language. Each problem’s forum is a kind of Rosetta stone. For a single simple problem you might find annotated solutions in Python, C, Assembler, BASIC, Ruby, Java, J and FORTRAN.

The first is that it’s naturally addictive. Computers are really fast; even in the ’80s they were really fast. What that means is there is almost no time between changing your program and seeing the results. That short feedback loop is mentally very powerful. Every few minutes you get a little payoff — perhaps a small hit of dopamine — as you hack and tweak, hack and tweak, and see that your program is a little bit better, a little bit closer to what you had in mind.

The second feature, by contrast, is something that at first glance looks totally immaterial. It’s the simple fact that code is text.